Practice TEAS Science Test

Correct Answer: B

Rationale: The correct answer is B: Hypothalamus. The hypothalamus is responsible for maintaining homeostasis in the body by regulating various bodily functions such as body temperature, thirst, hunger, sleep, and hormonal balance. It receives input from different parts of the body and initiates responses to maintain internal stability. The brainstem (A) is involved in basic life functions like breathing and heart rate but does not play a direct role in homeostasis. The medulla oblongata (C) controls involuntary functions like breathing and swallowing. The cerebrum (D) is responsible for higher brain functions like thinking and voluntary movements, not for maintaining homeostasis.

Correct Answer: B

Rationale: The correct answer is B: To filter waste from the blood. The kidneys play a crucial role in filtering waste products, excess substances, and toxins from the blood to form urine. This process helps maintain the body's overall balance of fluids and electrolytes. Choices A, C, and D are incorrect as the kidneys do not produce digestive enzymes (A), white blood cells (C), or red blood cells (D). The primary function of the kidneys is to regulate fluid and electrolyte balance, remove waste products, and help control blood pressure.

Correct Answer: B

Rationale: The correct answer is B: 12 NADPH and 18 ATP. In the Calvin cycle of photosynthesis, each molecule of CO2 requires 2 NADPH and 3 ATP for reduction to glucose. Therefore, to reduce 6 molecules of CO2, you would need 6 x 2 = 12 NADPH and 6 x 3 = 18 ATP. This is why choice B is the correct answer. Choices A, C, and D have incorrect combinations of NADPH and ATP that do not match the stoichiometry of the Calvin cycle for the reduction of CO2 to glucose.

Correct Answer: C

Rationale: The correct answer is C because an allergic reaction is triggered by the release of histamine and other inflammatory molecules from mast cells, which are stimulated by Immunoglobulin E. This process leads to symptoms such as hives, itching, swelling, and difficulty breathing. Other choices are incorrect because: A: While integumentary and respiratory systems are involved in allergic reactions, they are not overactive systems but rather respond to the allergen. B: B-cells produce antibodies, not immunoglobulins directly related to allergic reactions. D: Histamine is involved in allergic reactions, but keratin and collagen are not typically associated with allergic responses.

Correct Answer: D

Rationale: The correct answer is D: Glucose. Glucose is a monosaccharide, not a biological macromolecule. Biological macromolecules are large molecules made up of smaller subunits. Glycoproteins are proteins with attached carbohydrates, DNA is a nucleic acid, and phospholipids are lipids. Glucose, being a simple sugar, is not considered a macromolecule.